What Is an NRC Rating? How to Choose Acoustic Panels That Actually Work

NRC: The Number That Actually Matters

When comparing acoustic wall panels, the number you should be looking at first is the NRC rating — Noise Reduction Coefficient. It's the single most meaningful performance indicator for an acoustic product, and most retailers either don't publish it or bury it in the spec sheet.

Here's a plain-English explanation of what it means and how to use it.

What NRC Stands For

NRC — Noise Reduction Coefficient — is a number between 0 and 1 that represents the proportion of sound energy a material absorbs when sound waves strike it:

• NRC 0.0 = perfectly reflective. All sound bounces back. (Think: glass, concrete, polished stone.)
• NRC 0.5 = 50% of sound energy absorbed. Moderate absorption.
• NRC 0.85 = 85% absorbed. High performance. (Typical of quality acoustic slat panels.)
• NRC 1.0 = total absorption. Theoretical maximum — no real material achieves this.

How NRC Is Measured

NRC is measured in a standardised reverberant room (reverberation chamber) by testing how much a material reduces the room's reverberation time at four frequencies: 250Hz, 500Hz, 1000Hz, and 2000Hz. The NRC figure is the average across these four frequencies.

This means NRC is most representative of mid-range frequencies — the range that covers most speech, TV audio, and music. It doesn't capture performance at very low bass frequencies (below 125Hz) or very high frequencies (above 4000Hz).

What NRC Rating Do You Need?

This depends on the room and the problem you're solving:

• NRC 0.4–0.6: Noticeable improvement in rooms with moderate echo. Suitable for general living spaces where acoustic perfection isn't required.
• NRC 0.65–0.75: Significant improvement. Suitable for home offices, bedrooms, and living rooms where voice clarity and listening comfort matter.
• NRC 0.75–0.85: High performance. Suitable for home theatres, podcast studios, music rooms, and spaces where acoustic quality is a primary design criterion.
• NRC 0.85+: Professional grade. Often specified for recording studios, conference rooms, and commercial acoustic treatment.

Most quality acoustic slat panels with AcuFelt™ or equivalent felt backing achieve NRC 0.65–0.85, which covers the full range of residential applications comfortably.

NRC vs STC: A Common Confusion

NRC and STC (Sound Transmission Class) are frequently confused:

• NRC measures sound absorption within a room.
• STC measures sound blocking between rooms.

Acoustic wall panels have an NRC rating. They do not have a meaningful STC rating because they don't block sound — they absorb it. For a clear explanation of this distinction, see our guide on soundproof panels vs sound-absorbing panels.

Does Panel Coverage Affect Performance?

Yes, significantly. An NRC of 0.80 means 80% of sound that hits the panel is absorbed — but if the panels only cover 10% of the wall surface, most sound waves never hit them and continue reflecting off the bare walls.

General guidance for residential acoustic treatment:

• 25% wall coverage: Noticeable improvement, suitable for most living rooms and bedrooms
• 40–50% coverage: Substantial improvement, suitable for home offices and media rooms
• 60%+ coverage: Near-professional acoustic control, suitable for studios and dedicated home theatres

The easiest way to achieve 25–40% coverage without covering every wall is a single full feature wall of acoustic slat panels — which also happens to be the highest-impact aesthetic upgrade available. For the full picture on acoustic panel performance and selection, the complete acoustic wall panel buyers' guide covers everything in depth.

How to Read Product Listings

When evaluating acoustic slat panels:

1. Look for a stated NRC figure — not vague claims like "sound absorbing" or "acoustic"
2. Confirm the backing material — look for "felt backing," "acoustic felt," or "AcuFelt" rather than paper or foam
3. Check panel thickness — thicker panels generally absorb lower frequencies more effectively
4. Verify the species and veneer quality — real wood veneer vs laminate print makes a significant difference in longevity and appearance

NRC Ratings Room by Room: What to Target

The NRC rating you need depends on the room's purpose and how much hard surface area it has. These are practical targets based on real-world acoustic results:

Home office or meeting room: NRC 0.80–0.90. The goal is reducing echo on video calls and improving speech clarity. One well-placed panel wall — typically behind the monitor — is usually sufficient. A single wall of NRC 0.85 panels covering 80–100 sqft makes a measurable difference in call quality.

Living room or open-plan space: NRC 0.75–0.85. Rooms with hard floors, large windows, and minimal soft furnishings can feel live and echo-prone. Target 25–35% of total wall area with NRC 0.75+ panels. This is the threshold where most people notice a change without the room feeling acoustically dead.

Home theatre or dedicated listening room: NRC 0.85–1.00. Higher absorption targets matter here because you want the room's acoustic signature to be as neutral as possible — the audio equipment should define the sound, not the room. Target 40–60% coverage with the highest-rated panels available.

Podcast or recording studio: NRC 0.85+. The primary recording wall should have the highest-rated panels you can use. Side walls and ceiling can supplement. The goal is a short, controlled reverb tail — not a completely dead space, which sounds unnatural, but a room where you control what the microphone hears.

Bedroom: NRC 0.70–0.80. The goal here is general noise reduction and sleep quality improvement. Lower intensity than a studio, but still worth achieving. One feature wall with NRC 0.80 panels and soft furnishings elsewhere typically delivers results.

When in doubt, use the NRC value as a direct comparison tool: a panel rated NRC 0.85 absorbs 70% more sound energy per square metre than one rated NRC 0.50. That difference compounds significantly at scale.

Frequently Asked Questions

What is a good NRC rating for acoustic panels?

NRC 0.80 or higher is considered effective for domestic use. TPH SoundPanel has an NRC of 0.85, which puts it in the top tier for residential acoustic panels — comparable to professional fabric-wrapped panels at a fraction of the typical cost.

Is a higher NRC always better?

For most applications, yes. The exception is rooms where you want some natural reverb — a live music practice space, for example. In those cases, targeting NRC 0.60–0.70 and leaving harder surfaces exposed creates a balanced result.

How is NRC different from STC?

NRC (Noise Reduction Coefficient) measures how much sound a material absorbs within a room. STC (Sound Transmission Class) measures how much a construction assembly blocks sound from passing through. A wall panel can have a high NRC and a low STC — it absorbs sound inside the room but doesn't stop sound from transmitting to the next room.

Do acoustic panels need to cover the entire wall to work?

No. Coverage of 25–40% of total wall area is sufficient in most domestic rooms. Strategic placement — behind monitors, at primary reflection points, on the longest bare wall — delivers better results than full coverage at a lower NRC rating.

Why don't all acoustic panels publish NRC ratings?

NRC testing is done in a certified lab and costs money. Many decorative "acoustic" panels skip the certification because they're primarily sold on aesthetics, not performance. If a product doesn't publish an NRC rating, treat it as decorative.

A product without a published NRC rating is almost certainly decorative, not acoustic — regardless of how it's marketed.